That's where the org has to step in like u said cuz you're a pro player streaming in public, while contracted to an org that's under Riot's playground.
it is still not an excuse as I said, it's like you're allowing people from sea to say the n-word because they don't know the context (which actually happens dozens of times). How the org reprimands the player however is up to them, can be a small warning or something so he won't repeat it again in the future.